Method of welding.



C! PFNSTEEHL. mman o? Wmme.

PPLlC/sTiD/N FILED DEC. H; i917.

RWENT UF. E HEL FFHNETIEHL Ubi ITED STATES PATENT OFFICE.

CARL PFANSTIEHL, OF HIGHLAND PARK ILLINOIS, ASSIGNOR TOPFANSTIEI-ILJCOM- PANY, INCORPORATED, OF NORTH QHICAGO, ILLINOIS, ACORPORATION 0F NEN YORK.

METHOD OF WELDING.

Specication of Letters Patent.

Patented Jan. 21, 191.9.

- To all whom it may concern:

Be it known that I, CARL PFANSTIEHL, a citizen of the United States,residing at Highland Park, in the county of Lake and State of Illinois,haveinvcnted a. certain new and useful Improvement in Methods oflVelding, of which the following is a full, clear, concise, and exactdescription, reference being had to the accompanying drawings. forming apart of this specification.

This invention relates to a method of welding. The invention isparticularly con` cerned with and is illustrated in connection with themethod of uniting a. valve head of high speed steel to a valve stem oflow speed steel.

Heretoforc considerable difliculty has been experienced in securing anefficient weld bctween high speed steels and low speed steels, the termhigh speed being used to include tungsten and other similar alloys ofsteel, and the term low speed being used to designate carbon and nickelsteels having varying percentages et carbon or nickel. It is one of theobjects of this invention to rovidc a method for welding steels of thekind referred to which will produce a substantially homogeneous jointbetween the two metals, the joint being characterized by a blending ofthe two different metals into each other rather thanby a distinct lineof separation suchas has resulted from methods heretofore in use. Q

Further objects will ,appear as the description of my improved processprogresses, reference being made to the accom-A K panying drawings inwhich,

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Figure 1 is a side elevation of the disk from which the head of myimproved valve is formed;

Fig. 2 is a central sectionvthrough the head formed from the disk shownin Fig. 1;

F ig. 3 is amore or less diagrammatical cross section through theapparatus I employ for carrying out my improved process showing thevalve stem and head in the position they occupy at the beginning of thewelding process;

Fig. 4 is a view similar to Fig. 3, portions of the apparatus beingbroken away', showing the valve stem and head at the end of the weldingoperation; and

electrodes 13 and 17 5 is a side elevation of the completed Similarcharacters of reference refer to similar parts throughout the severalviews.

In carrying out my improved process the Valve heads are formed by firstpunching disks 10 from a sheet of the alloy of-which it is desired toconstruct the "alve head. These disks are then placed in suitable diesand are conformed, as shown in F ig. 2, and at the same time an aperture11 is formed in the bottom of the conical boss 12 which tapersoutwardly. The head thus formed is placed upon the massive copperelectrode 13 in an inverted position. Thel electrode 13 is provided witha central conical boss or projection 14 the curvature of whichsubstantially corresponds to the curvature of the head when finished.The curvature of the head shown in Fig. 2 is such, however, that whenplaced in inverted position upon the electrode 13 only the outer edgesthereof contact with the electrode thus leaving the central portions ofthe concave side of the valve head spaced from the adjacent surfaces ofthe electrode. The electrode 13 is provided with a bore 15 whichregisters with the tapered hole 11 in the valve head.

For conducting currentto the valve stem 16 a pair of electrodes 17 areemployed which are provided with opposed grooves for receiving the valvestem 1C. Means, not shown, are, provided for pressing the valve stem 1Gdownwardly upon the, valve' head 10. These means are not illustrated forthe reason that various means for performing this function are in useand well known to those skilled in this art. A sleeve 18 is slidablymounted upon either the electrode 13 or the electrode 17 so that it maybe displaced to permit the valve head and stem to be inserted in themachine. The function of this sleeve is to hold hydrogen or othernon-oxidizing gas which is used for displacing the air from the spaceabout the valve head during the welding` operation, the air escapingbetween the sleeve and the electrodes or through any other suitableopening. The hydrogen gas is introduced into the sleeve through the bore19 in one of the electrodes 117.

After the valve head and stem have been brought into the relation shownin Fig. 3 the are connected with the opposite terminals of a suitablesource of electricity and pressure is'applied to the valve stem 16 tourge it toward the electrode 13. When the current is first turned on itpasses through the valve stem 16 to the valveof are in cont-act with thesaid electrode.

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The current continues to flow in this path until the valve head isheated up to the oint where the pressure exerted on the valve stem 16 issuiiicient to push the central portion of the valve head down againstthe ceitral portion of the electrode 13. Most of the current then flowsstraight across the central portion of the valve head 'from the valvestem 16 to the end of the conical extension 14 of the electrode 13although sulfieient current still flows through the outer portions ofthe valve head to maintain these portions at a substantially red heat.As the current continues to flow through the central portion of thevalve head it causes the lower end of the valve stem to fuse and thepressure being constantly exerted upon' the valve stem the fused metalis forced outwardly, as shown in Fig. 4, fgrming a collar v20 whichhardens as it comes in contact with the comparatively cool portions ofthe electrodes 17. The metal is thus confined by this collar 20 fromescaping in this direction and a portion of the fused metal is extrudedthrough the opening 11 in the valve head andpasses into the bore 15 ofthe electrode 13. As the forward end of this extruded metal comes incontact with the walls of the bore 15 a new path for the current isestablished and the current flowing through this extruded portion of thevalve stem maintains it at a very high temperature and as the metalpasses along in contact with the walls of the hole 11 the latter aregradually heated up to the fusing point of the metal from which thevalve head is formed. The movement of these two metals relative to eachother causes a certain mixing of the fused metals and at this point thecurrentsupply is shut off. The collar 20, by preventing the escape ofmetal outwardly, causes sufficient heat to be retained at the contactingsurfaces of the stem and valve head to bring this surface of the valvehead to the fusing point and inasmuch as the fusing point of the metalof the valve head is considerably higher than that of the metal of thevalve stem the fused metal of the valve stem is heated to such a degreethat it boils, thereby causing a mixture of the metals of the valve stemand the valve head. After the current is shut off and the valve cooledthere is a substantially homogeneous mixture of the metals of the twomembers all along the contacting surfaces thereof. The collar Q0 isthenremoved by a suitable turning operation and the tea of the valvemachined and ground as desired.` The extruded metal 21 is removed and ifdesired a slot- 22 can be milled in the head of 'the valve to assist inthe turning operation.

The spacing of the central portions of the valve head from the lowerelectrode during the preliminary heating of the valve head is ofimportance for the reason that if it was attempted to heat the centralportion of the valve head up to the fusing or welding point withoutheating the outer portions of the valve head very severe internalstresses would be set up in the valve upon the cooling of the centralportion thereof which would cause the valve head to be fractured veryeasily. This condition, however, is avoided by first heating the outerportions of the valve up to a substantially red heat. y

The projection 14, in addition to constituting a part of the path forthe current flowing across the valve head, serves to withdraw heat fromthe lower side of the valve head and thus prevents the central portionof the valve head from being fused entirely through.

l/Vhile I have described my inventionA in connection with themanufacture of a valve comprising a valve head anda valve stem formed ofdifferent metals it is to be understood that my improved process iscapable of being used for uniting other pieces of metal having eitherdifferent or substantially the ame melting points and it is not confinedto the joining of rod shapedpieces of metal with pieces of sheet metal.My invention is, therefore, not to be limited except b -r tl scope ofthe following claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. The process of welding a plate of one metal to a rod of another metalwhich comprises the steps of forming a tapered hole through the plate,bringing one end of the rod adjacent the plate so as to cover thesmalljend of the tapered hole, applying pressure t'o said rod to pressit against said plate, passing an electric current through thecontacting portions of said rod and plate while the pressure is'beingapplied, conducting the heat away from the side of the plate oppo1 sitethe rod after the plate has been heated to a substantially red heat andallowing the current to ilow until the metal of the rod iiows throughthe hole in said plate and fuses the walls thereof.

2, The process of welding a plate of one -metal to a rod of anothermetal which comprises the steps of forming a tapered hole through theplate, bringing one end of the rod adjacent the plate so as to cover thesmall end of the tapered hole, applying pressure to said rod to 'pressit against said plate, passing an electric current through thecontacting portions of said rod and plate while the pressure is beingapplied, and allowing the current to iiow until the metal of the rodflows through the hole in said plate and fuses the walls thereof.

3. The process of welding a plate of one metal to a rod of another metalwhich comthe plate,

prises the steps of 'forming a hole through bringing one end of the rodadjacent the plate so as to cover the end of the hole, applying pressureto said rod to press it against said plate, passing an electric currentthrough the contacting portions of said rod and plate while the pressureis being applied, conducting the heat away from the side of the plateopposite the rod after the plate has been heated to a substantially redheat and allowing the current to flow until the metal of the rod flowsthrough the hole in said 'plate and fuses the walls thereof.

4. The process of welding a plate of one metal to a rod of another metalwhich comprises Lthe .steps of forming'a hole through the plate,bringing one end of the rod adjacent the plate so a-s-to cover the endof the hole, applying pressure to said rod to press it against saidplate, passing an electric current through the contacting portions ofsaid rod and plate while the pressure is being applied, and allowing thecurrent to flow until the metal of the rod flows through the hole insaid plate and fuses the walls thereof.

5. The process of welding a rod to a plate which comprises the steps offorming a tapered hole in said plate. bringing the end et the rod intoContact with said plate so as to cover the small end of said hole,applying pressure to force said rod and plate together', heating the rodand plate at their juncture until the metal of the rod passes throughsaid hole and fuses the Walls thereof, and then cooling said joint.

6. The process of welding a rod to a. plate which comprises the steps offorming a hole through said plate, bringing the end of the rod intocontact with said plate so as to coverone end of said hole, and applyingpressure and heat to the rod and vplate at the point of contact untilthe metal of the rod flows through said hole and fuses the wallsthereof.

7. The process of joining two pieces of metal which comprises the stepsof forming a hole in one piece, bringing the other piece into contacttherewith so as to close said hole, and applying pressure to force saidpieces together while current is caused to pass through said pieces attheir point of contact until'the metal of the piece of lower meltingpoint fuses and flows into the hole of the other piece.

8. The process of uniting pieces of mtal which comprises the steps offorming a hole in one piece, and simultaneously fusing and extruding aportion of the metal of lower melting point through the said hole untilthe metals of the two pieces become mixed.

9. The process of uniting pieces of metal of different melting pointswhich comprises the steps of simultaneously fusing and eX- truding aportion of the metal of lower melting point through the metal of highermelting point.

l0. The process of uniting two pieces of metal which comprises the stepsof simultaneously fusing and eXtruding a portion of one piece throughthe other piece.

11. The process ofuniting two pieces of metal'which comprises the stepsof forming a hole in one or' said pieces, bringing the pieces together,fusing the metal of the other icce and causing it to pass through saidllole until the walls of the hole reach a Welding temperature. A

l2. The process of uniting two pieces of metal which comprises the stepsof forming a hole through one of said pieces, eXtruding a portion ot'the other piece through said hole in close contact with the wallsthereof, and causing an electric current to pass through said extrudingportion until the walls of the hole are heated to welding teinperature.

In witness whereof, I hereunto subscribe my name this 11th day ofDecember, A. D.

CARL PFANSTIEHL. 1l/Vitnesses linntmnn'r GnoBBuN, inem: SCHUMANN.

